Investments - Fixed Maturities and Equity Securities (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Available-for-sale Securities Including Securities Pledged [Line Items]
Securities pledged, amortized costs	$ 875	$ 894
Debt Securities, Available-for-sale, Allowance for Credit Loss	12	7
U.S. Treasuries
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	303	404
Fixed maturities, Gross Unrealized Capital Gains	4	4
Fixed maturities, Gross Unrealized Capital Losses	23	31
Embedded Derivatives	0	0
Fair Value	284	377
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
US Treasury and Government
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	33	33
Fixed maturities, Gross Unrealized Capital Gains	0	0
Fixed maturities, Gross Unrealized Capital Losses	3	3
Embedded Derivatives	0	0
Fair Value	30	30
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
State, municipalities and political subdivisions
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	664	691
Fixed maturities, Gross Unrealized Capital Gains	1	1
Fixed maturities, Gross Unrealized Capital Losses	76	92
Embedded Derivatives	0	0
Fair Value	589	600
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
U.S. corporate public securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	6,641	6,938
Fixed maturities, Gross Unrealized Capital Gains	42	32
Fixed maturities, Gross Unrealized Capital Losses	902	1,032
Embedded Derivatives	0	0
Fair Value	5,780	5,938
Debt Securities, Available-for-sale, Allowance for Credit Loss	1
OTTI		0
U.S. corporate private securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	3,914	3,885
Fixed maturities, Gross Unrealized Capital Gains	19	11
Fixed maturities, Gross Unrealized Capital Losses	325	328
Embedded Derivatives	0	0
Fair Value	3,608	3,568
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
Foreign corporate public securities and foreign governments
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	2,262	2,380
Fixed maturities, Gross Unrealized Capital Gains	14	9
Fixed maturities, Gross Unrealized Capital Losses	266	317
Embedded Derivatives	0	0
Fair Value	2,007	2,066
Debt Securities, Available-for-sale, Allowance for Credit Loss	3
OTTI		6
Foreign corporate private securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	2,495	2,617
Fixed maturities, Gross Unrealized Capital Gains	14	6
Fixed maturities, Gross Unrealized Capital Losses	158	184
Embedded Derivatives	0	0
Fair Value	2,350	2,438
Debt Securities, Available-for-sale, Allowance for Credit Loss	1
OTTI		1
Residential mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	2,748	3,023
Fixed maturities, Gross Unrealized Capital Gains	22	21
Fixed maturities, Gross Unrealized Capital Losses	141	153
Embedded Derivatives	(1)	(2)
Fair Value	2,630	2,893
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
Commercial mortgage-backed
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	2,896	2,978
Fixed maturities, Gross Unrealized Capital Gains	0	0
Fixed maturities, Gross Unrealized Capital Losses	418	379
Embedded Derivatives	0	0
Fair Value	2,471	2,599
Debt Securities, Available-for-sale, Allowance for Credit Loss	7
OTTI		0
Other asset-backed securities
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	1,485	1,418
Fixed maturities, Gross Unrealized Capital Gains	2	1
Fixed maturities, Gross Unrealized Capital Losses	85	109
Embedded Derivatives	0	0
Fair Value	1,402	1,310
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
OTTI		0
Embedded derivatives - fixed maturities
Available-for-sale Securities Including Securities Pledged [Line Items]
Amortized Cost	23,441	24,367
Fixed maturities, Gross Unrealized Capital Gains	118	85
Fixed maturities, Gross Unrealized Capital Losses	2,397	2,628
Embedded Derivatives	(1)	(2)
Fair Value	21,151	21,819
Total fixed maturities, less securities pledged, Amortized Cost	22,566	23,473
Total fixed maturities, less securities pledged, Gross Unrealized Capital Gains	118	82
Total fixed maturities, less securities pledged, Fair Value	20,362	21,027
Debt Securities, Available-for-sale, Allowance for Credit Loss	12
OTTI	12	7
Total fixed maturities, less securities pledged, Gross Unrealized Capital Losses	2,311	2,523
Collateral Pledged
Available-for-sale Securities Including Securities Pledged [Line Items]
Securities pledged	789	792
Collateral Pledged | Embedded derivatives - fixed maturities
Available-for-sale Securities Including Securities Pledged [Line Items]
Embedded Derivatives	0	0
Securities pledged, amortized costs	875	894
Securities pledged, Gross Unrealized Capital Gains	0	3
Securities pledged	789	792
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Available-for-sale Securities, Pledged as Collateral, Debt Securities, Unrecognized Holding Loss	$ 86	$ 105